Therapeutic eye treatment with gases

ABSTRACT

An apparatus to maintain an environment over an anterior surface of a patient eye can include an enclosure sized and shaped to be seated about the patient eye to form a cavity within the enclosure. The enclosure can be configured to contain a fluid other than ambient air in contact with the patient eye. The apparatus can include a fluid regulator in communication with the enclosure, where the fluid regulator can be configured to regulate the composition of the fluid contained within the enclosure.

CLAIM OF PRIORITY

This patent application is a continuation of U.S. patent applicationSer. No. 17/014,631, filed Sep. 8, 2020, entitled “DEVICES AND METHODSFOR HUMIDITY CONTROL OVER AN EYE”, which is a continuation of U.S.patent application Ser. No. 16/083,302, filed Sep. 7, 2018, entitled“THERAPEUTIC EYE TREATMENT WITH GASES” which a U.S. National StageFiling under 35 U.S.C. 371 from International Application No.PCT/US2017/021240, filed on Mar. 8, 2017, which claims the benefit ofpriority of U.S. Provisional Patent Application Ser. No. 62/305,751,entitled “Therapeutic Eye Treatment with Gases,” filed on Mar. 9, 2016,all of which are hereby incorporated by reference their entireties.

BACKGROUND

Patient compliance in applying therapeutic substances to an eye isimportant in treating diseases of the eye, such as glaucoma. Topicalmedications, such as eye drops, can drain quickly from the eye therebyminimizing contact time with absorbing surfaces, such as the cornea,sclera, and conjunctiva.

Kang U.S. Pat. No. 5,807,357 mentions a compact nebulizer for treatingthe eyes including a goggles unit having an air hole and at least oneair chamber communicating with the air hole and fitting over the user'seyes. A plurality of exhausting holes are made at the goggle unit forexhaust air.

Skiba U.S. Patent Application No. 2002/0124843 mentions a mask wornaround the eyes with one or more fog outlets an atomizer to nebulizemedicine into a fog such that the fog discharges from the fog outlets todelivery medicine to one or more eyes.

Guillon U.S. Patent Application No. 2007/0265505 mentions an eyeenclosure adapted to provide an enclosed area about the eyes of theuser, a means for retaining the eye enclosure in position, and means forsupplying dry air to the eye enclosure.

OVERVIEW

The present inventors have recognized, among other things, that there isa need in the art for methods and devices that will allow for thedelivery of therapeutic gases, such as carbon dioxide (CO₂), oxygen(O₂), nitric oxide (NO), ozone (O₃), nitrogen, hydrocarbons includingfluorocarbons and perfluorocarbons, sulfur hexafluoride, andcombinations of therapeutic substances, such as a mixture of nitricoxide and oxygen, including a mixture of 50% nitric oxide and 50%oxygen, a mixture of helium and oxygen, also known as heliox, andMedical Air, through the surfaces of the eye, such as the corneal,scleral, and conjunctival surfaces, over an extended period time. Newtherapeutic techniques, such as applying a therapeutic force to theanterior portion of the eye, can supplement pharmacological regimens.Enhanced patient outcomes can be realized by combining therapeuticsubstances with new techniques.

This document describes, among other things, methods and apparatuses forintroducing gaseous fluids to an eye to treat an eye condition. Themethod can include providing an enclosure. The enclosure can be sizedand shaped to be seated about an eye and form a cavity within theenclosure. A gaseous fluid other than ambient air can be introduced intothe cavity, such as to provide therapy to the eye. The gaseous fluid caninclude a specified non-ambient concentration of at least one of carbondioxide (CO₂), oxygen (O₂), or nitric oxide (N₂O).

An overview of certain non-limiting aspects of the present subjectmatter is provided below.

Aspect 1 can include or use subject matter (such as an apparatus, asystem, a device, a method, a means for performing acts, or a devicereadable medium including instructions that, when performed by thedevice, can cause the device to perform acts), such as an apparatus tomaintain an environment over an anterior surface of a patient eye. Anenclosure sized and shaped to be seated about the patient eye can form acavity within the enclosure. The enclosure can be configured to containa fluid other than ambient air such as the fluid can be in contact withthe patient eye. A fluid regulator can be in communication with theenclosure. The fluid regulator can be configured to regulate thecomposition of the fluid contained within the enclosure.

Aspect 2 can include or use, or can optionally be combined with thesubject matter of Aspect 1 to optionally include or use the enclosureconfigured to maintain a differential fluid pressure between the cavityand the surrounding environment and the fluid regulator is configured toregulate the differential pressure of the fluid contained within theenclosure.

Aspect 3 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 or 2 to optionallyinclude or use a fluid that can include a gaseous fluid.

Aspect 4 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 3 tooptionally include or use the gaseous fluid wherein the gaseous fluidincludes a specified non-ambient percentage of at least one of carbondioxide (CO₂), oxygen (O₂), or nitric oxide (NO).

Aspect 5 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 4 tooptionally include or use the gaseous fluid wherein the gaseous fluidincludes a specified non-ambient percentage of carbon dioxide (CO₂).

Aspect 6 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 5 tooptionally include or use the gaseous fluid wherein the gaseous fluidincludes a specified non-ambient percentage of oxygen (O₂).

Aspect 7 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 6 tooptionally include or use the gaseous fluid wherein the gaseous fluidincludes a specified non-ambient percentage of nitric oxide (NO).

Aspect 8 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 7 tooptionally include or use a sensor configured to detect at least one ofan indication of the eye or an indication of a parameter of anenvironment within the cavity.

Aspect 9 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 8 tooptionally include or use the sensor wherein the sensor includes anoptical coherence tomography (OCT) system.

Aspect 10 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 9 tooptionally include or use the sensor wherein the sensor includes anon-contact blood vessel characteristic detector.

Aspect 11 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 10 tooptionally include or use the sensor wherein the sensor includes aquartz crystal nanobalance sensor.

Aspect 12 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 11 tooptionally include or use the sensor wherein the sensor includes anon-invasive optical oxygen sensor.

Aspect 13 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 12 tooptionally include or use the sensor wherein the sensor includes asalinity sensor.

Aspect 14 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 13 tooptionally include or use the sensor wherein the sensor includes anaptamer-based sensor.

Aspect 15 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 14 tooptionally include or use a processor module in communication with atleast one of the fluid regulator or a sensor.

Aspect 16 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 15 tooptionally include or use the processor wherein the processor module isin communication with the fluid regulator.

Aspect 17 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 16 tooptionally include or use the processor wherein the processor unit is incommunication with the sensor. Aspect 18 can include or use, or canoptionally be combined with the subject matter of one or any combinationof Aspects 1 through 17 to optionally include or use a pump incommunication with at least one of the processor or the enclosure.

Aspect 19 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 18 tooptionally include or use the pump wherein the pump is in communicationwith the processor.

Aspect 20 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 19 tooptionally include or use the pump wherein the pump is in communicationwith the enclosure.

Aspect 21 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 20 tooptionally include or use the pump wherein the pump is a vacuum pump.

Aspect 22 can include or use subject matter (such as an apparatus, asystem, a device, a method, a means for performing acts, or a devicereadable medium including instructions that, when performed by thedevice, can cause the device to perform acts), or can optionally becombined with the subject matter of one or any combination of Aspects 1through 21 to optionally include or use or provide an enclosure that issized and shaped to be seated about the patient eye to form a cavitywithin the enclosure. At the enclosure, a fluid other than ambient aircan be provided to the cavity such as to treat an eye condition.

Aspect 23 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 22 tooptionally include or use providing a fluid to maintain a differentialfluid pressure between the cavity and the surrounding environment.

Aspect 24 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 23 tooptionally include or use sensing an indication of the fluid other thanambient air in the cavity.

Aspect 25 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 24 tooptionally include or use sensing wherein sensing an indication includessensing an indication of at least one of fluid pressure, fluid partialpressure, fluid concentration, or fluid humidity.

Aspect 26 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 25 tooptionally include or use sensing wherein sensing an indication of fluidpartial pressure includes sensing a fluid partial pressure of at leastone of carbon dioxide (CO₂), oxygen (O₂), nitric oxide (NO), ketones,glucose, oxygen levels, dissolved salts, or vascular endothelial growthfactor.

Aspect 27 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 26 tooptionally include or use sensing wherein sensing an indication of fluidconcentration includes sensing a concentration of at least one of carbondioxide (CO₂), oxygen (O₂), nitric oxide (NO), ketones, glucose, oxygenlevels, dissolved salts, or vascular endothelial growth factor.

Aspect 28 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 27 tooptionally include or use sensing an indication of the patient eye.

Aspect 29 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 28 tooptionally include or use sensing wherein sensing an indication of thepatient eye includes sensing an indication of at least one of anindication of intraocular pressure, an indication of translaminarpressure, or an indication of intracranial pressure.

Aspect 30 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 29 tooptionally include or use sensing wherein sensing an indication oftranslaminar pressure includes sensing an indication of at least one ofa deflection of the lamina cribrosa, a change in deflection of thelamina cribrosa, or a change in a blood vessel characteristic.

Aspect 31 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 30 tooptionally include or use adjusting an indication of the fluid otherthan ambient air.

Aspect 32 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 31 tooptionally include or use adjusting wherein adjusting an indicationincludes adjusting an indication of at least one of fluid pressure,fluid partial pressure, fluid concentration, or fluid humidity.

Aspect 33 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 32 tooptionally include or use or provide a gaseous fluid including a gaseousfluid with a specified non-ambient concentration of at least one ofcarbon dioxide (CO₂), oxygen (O₂), nitric oxide (NO), ozone (O₃),nitrogen, hydrocarbons, helium, sulfur hexafluoride, Medical Air, orwater vapor.

Aspect 34 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 33 tooptionally include or use receiving a patient with an eye condition thatincludes at least one of Fuchs' dystrophy, glaucoma, dry eye, diabeticretinopathy, cataract, venous and arterial occlusive diseases, maculardegeneration, diseases of the cornea, endothelium, and epithelium,diseases of the retinal vasculature, diseases of the retinal pigmentedepithelium, corneal infections, or other infections of the eye.

Aspect 35 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 34 tooptionally include or use providing wherein providing a fluid includesproviding a gaseous fluid with a partial pressure between 30 percent and100 percent oxygen (O₂).

Aspect 36 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 35 tooptionally include or use a gaseous fluid wherein the gaseous fluidincludes a specified concentration of carbon dioxide (CO₂).

Aspect 37 can include or use, or can optionally be combined with thesubject matter of one or any combination of Aspects 1 through 36 tooptionally include or use a gaseous fluid wherein the gaseous fluidincludes a specified concentration of nitric oxide (NO).

This overview is intended to provide an overview of subject matter ofthe present patent application. It is not intended to provide anexclusive or exhaustive explanation of the invention. The detaileddescription is included to provide further information about the presentpatent application.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentdocument.

FIG. 1A shows an example of an apparatus, such as for introducingtherapeutic gases to an eye.

FIG. 1B shows an example of a manifold, such as attached to theapparatus of FIG. 1A.

FIG. 2A shows a first example of a wicking gasket.

FIG. 2B shows a second example of a wicking gasket.

FIG. 3 shows a cross-section of an example wicking gasket attached to anenclosure.

FIG. 4 shows a bottom view of an example wicking gasket with a suctiontube, the wicking gasket attached to an enclosure.

FIG. 5 shows an example method for introducing a gaseous fluid otherthan ambient air into one or more cavities within the enclosure.

FIG. 6 shows an example method of sensing an indication with theapparatus.

FIG. 7 shows an example method for varying the composition of thegaseous fluid within the cavity.

FIG. 8 shows an example method for receiving a patient.

FIG. 9 shows an example of a treatment for Fuchs' dystrophy.

FIG. 10 shows an example method to introduce gaseous fluids into thecavity with a positive gauge pressure.

FIG. 11 shows an example method to introduce gaseous fluids into thecavity with a negative gauge pressure.

FIG. 12 shows an example method to control the level of water vapor inthe cavity.

DETAILED DESCRIPTION

This document describes examples of devices and methods forestablishing, maintaining, and controlling a therapeutic environment incontact with a patient eye, such as to provide for the treatment of eyeconditions with different treatment modalities simultaneously.

In an example, the present devices can include a goggle, such as a pairof goggles, located over the eye of the patient. The goggle can includean enclosure that defines a cavity, such as the cavity between theinterior surface of the enclosure and the patient when the enclosure canbe located over the eye of the patient, and a fluid regulator, such asto control delivery of fluid including a fluid other than ambient air tothe cavity. An environment, such as a therapeutic environment, can beestablished within the cavity, such as to treat an eye conditionassociated with the patient eye. The eye condition to be treated candictate the therapeutic environment required to be maintained in thecavity. In an example, the therapeutic environment within the cavity canbe characterized with system parameters.

In an example, the present devices can include a goggle, a fluidregulator, a sensor in proximity to the goggle, a pump in fluidiccommunication with the goggle, and a processing module in electricalcommunication with at least one of the fluid regulator, the sensor, orthe pump. An environment, such as a therapeutic environment, can beestablished, maintained, and controlled within the cavity, such as witha closed-loop controller, to treat an eye condition associated with thepatient eye.

A first system parameter of the therapeutic environment can include thecomposition of the fluid in the cavity, such as the composition of theconstituent fluids that can form the therapeutic environment. As thetherapeutic environment can be in contact with the surface of the eye,the partial pressure of one or more constituent fluids in the cavity canbe used to treat an eye condition, such as through absorption of the oneor more constituent fluids through the anterior portion of the eye. Inan example, swelling of the cornea, such as associated with Fuchsdystrophy, can be treated by exposing the cornea to a therapeuticenvironment, such as a therapeutic environment with a non-ambient volumeconcentration of gaseous oxygen (O₂). In an example, the therapeuticenvironment in the cavity 112 can be applied to the eye at an ambientpressure, such as the pressure in the cavity 112 can be equal to orapproximately equal to the pressure of the environment surrounding theenclosure 110.

A second system parameter of the therapeutic environment can include thegauge pressure of the therapeutic environment, such as the differentialpressure between the therapeutic environment in the cavity and theambient surroundings. The gauge pressure of the fluid in the cavity canbe used to treat an eye condition, such as by applying a mechanicalforce to the eye. In an example, symptoms of glaucoma, such as elevatedintraocular or translaminar pressure, can be treated by applying anegative gauge pressure to the cavity, such as to allow a volumeexpansion of the eye to reduce intraocular pressure or equalizetranslaminar pressure of the patient eye.

In an example, a combination of system parameters, such as gaugepressure and fluid composition, can be used to improve the treatment ofan eye condition, such as by simultaneously treating the eye conditionwith more than one treatment modality. In an example, macular edema,such as due to fluid accumulation in the macula of the eye, can betreated in a therapeutic environment with a combination of positivegauge pressure, such as to equalize the translaminar pressure differencein the eye to reduce macular swelling, and with a therapeutic fluid,such as with a substance known to increase vasodilation including anon-ambient volume concentration of at least one of carbon dioxide (CO₂)or nitric oxide (NO).

FIG. 1A shows an example of an apparatus 100, such as for forming atherapeutic environment over an eye. The apparatus 100 can include anenclosure 110, such as a first enclosure 110A and a second enclosure110B, a fluid regulator 120, a sensor 130, a processor module 140, and apump 150, such as in communication with the processor module 140.

The enclosure 110 can be sized and shaped to surround a patient eye andbe spaced from the eye, such as without contacting the eye. Theenclosure 110 can define an enclosed cavity 112 when the enclosure 110is placed against the patient, such as a cavity 112 between an innersurface of the enclosure 110 and the patient eye. The enclosure 110 canbe constructed from an optically transparent material such as to allow apatient to see outward through the enclosure 110 or to allow observationof the eye inward through the enclosure 110. The inner surface of theenclosure 110 can be treated, such as with an anti-fog coating toprevent condensation from obscuring the view of the patient. Theenclosure 110 can include a hole 113, such as a plurality of holes 113,to allow for drainage of condensate from the cavity 112. In an example,the diameter of the hole 113 can vary, such as in a range of from about1 mm to about 10 mm. The enclosure 110 can include a gasket 114, such asa gasket located around at least a portion of a perimeter of theenclosure 110. The enclosure 110 can be positioned over the eye, such asthe gasket 114 can be located against the skin of the patient, such asto form a hermetic seal between the enclosure 110 and the skin, toisolate the cavity 112 from the surrounding environment. In an examplethe gasket 114 can include a wicking gasket 160, such as a gasket thatcan receive and retain a fluid, such as a condensate, that can appear inthe cavity 112 during the operation of the apparatus 100.

FIG. 2A shows a first example of a wicking gasket 160. The wickinggasket 160 can include a wicking core 162 with a first surface 163 and acore cover 166 with an interior surface 167 and an exterior surface 168.The wicking gasket 162 and core cover 166 can contact the skin, such asat least a portion of the first surface 163 and the exterior surface 168can contact the skin, to absorb condensate, such as water, sweat, orother liquid fluids in the cavity 112. Removing excess condensate fromthe cavity 112 can improve patient comfort during use of the apparatus100.

The wicking core 162 can be constructed from an absorbing material, suchas a material that can use capillary action to transfer fluid from afirst location to a second location, such as expandedpolytetrafluoroethylene (or PTFE). The core cover 166 can be constructedfrom a porous material, such as a material with a porosity selected toachieve a specified migration rate of condensate through the wickinggasket 160, the material selected to minimize discomfort caused by theenclosure 110 when placed against the skin of the patient, such as forextended time periods. In an example, the core cover 166, such as theinterior surface 167, can encapsulate the wicking core 162, such as atleast a specified portion or surface area percentage of the firstsurface 163.

FIG. 2B shows a second example of a wicking gasket 160. The core cover166 can substantially encapsulate the wicking core 162 and can include areceiving hole 165, such as a plurality of receiving holes 165,extending through the core cover 166, such as from the interior surface167 to the exterior surface 168. The receiving hole 165 can place thewicking core 162 in communication with the cavity 112, such ascondensate can flow from the cavity 112 through the receiving hole 165to the wicking core 162, to remove condensate from the cavity 112.

FIG. 3 shows a cross-section of an example wicking gasket 160 attachedto an enclosure 110, such as the perimeter of the enclosure 110. Inoperation, the wicking gasket 160 can be located against a patient, suchas in contact with the skin of the patient, to separate the cavity 112from the surrounding environment. The wicking core 162 can be incommunication with the cavity 112 to absorb accumulated condensate, suchas through the receiving hole 165. In an example, absorbed condensatecan migrate through the wicking core 162 and the core cover 166, such asto evaporate from the exterior surface 168 exposed to the surroundingenvironment.

FIG. 4 shows a bottom view of an example wicking gasket 160 with asuction tube 169, the wicking gasket 160 attached to an enclosure 110.In an example, the suction tube 169 can be attached to the core cover166 and the lumen of the suction tube 169 can be in communication withthe wicking core 162. A negative gauge pressure can be generated in thelumen of the suction tube 169 and applied to a surface of the wickingcore 162, such as to cause migration of condensate absorbed by thewicking core 162 through the wicking core 162 to the suction tube 169,such as to remove the condensate from the cavity 112. Negative gaugepressure can be generated by a condensate pump attached to the suctiontube 169. In an example, the condensate pump can include a pump separatefrom the apparatus 100, such as a standalone pump that can generate avacuum, and a pump included in the apparatus 100, such as the pump 150.

The enclosure 110 can be secured to the patient to locate the enclosure110 over the eye of the patient, such as with an adjustable strapattached to the enclosure 110, the adjustable strap substantiallyencircling the head.

The enclosure 110 can maintain a differential fluid pressure, such as agauge pressure, between the cavity 112 and another pressure region, suchas the atmosphere surrounding the enclosure 110. The fluid containedwithin the cavity 112 can exert a pressure on an anterior surface of theeye, such as to apply a therapeutic force to the eye to treat an eyecondition. In an example, a positive gauge pressure can exert atherapeutic compressive force on the eye, such as to increase theintraocular pressure (or IOP) of the eye. In an example, a negativegauge pressure can exert a therapeutic vacuum force on the eye, such asto decrease the IOP of the eye.

The cavity 112 can contain a fluid, such as a therapeutic fluidincluding a fluid other than ambient air, in contact with the eye. Thetherapeutic fluid can be absorbed by the eye, such as through theanterior surface of the eye, to treat an eye condition. In an example,the therapeutic fluid can be composed of a medicinal fluid, such as aliquid fluid and a gaseous fluid.

A therapeutic fluid can include a medicinal fluid, such as a liquidfluid including a miscible solution, such as an aqueous solution, and acolloidal suspension. Aqueous solutions can include therapeuticsubstances, such as medications and vitamins, dissolved in water. In anexample, medications can include anesthetic drops, antibiotics, orsubstances to diagnose and treat glaucoma. In an example, thetherapeutic fluid can be aerosolized, such as to create a mist or fog oftherapeutic fluid.

A therapeutic fluid can include a medicinal fluid, such as a gaseousfluid including a therapeutic gas. A therapeutic gas can include carbondioxide (CO₂), oxygen (O₂), nitric oxide (NO), ozone (03), nitrogen,helium (He), hydrocarbons including fluorocarbons and perfluorocarbons,sulfur hexafluoride, and combinations of therapeutic gases. In anexample, a therapeutic gas can include a mixture of at least one ofcarbon dioxide, oxygen, or nitric oxide. In an example, a therapeuticgas can include a mixture of nitric oxide and oxygen including a mixtureof 50% nitric oxide and 50% oxygen, a mixture of helium and oxygen (alsoknown as heliox), and Medical Air, such as Medical Grade Air USP. In anexample, a combination of therapeutic gases can include a mixture ofnitric oxide and oxygen, such as a mixture of 50% nitric oxide and 50%oxygen including gases from The BOC Group plc under the tradenameENTONOX. In an example, a mixture can include a mixture of helium andoxygen, such as a mixture of 21% oxygen and 79% helium, also known asheliox.

The combination of applying a therapeutic fluid, such as other thanambient air, to a cavity 112 at a gauge pressure, such as to generate atherapeutic force against the eye, can allow for simultaneous,multi-modal therapeutic treatment of the patient eye. In an example, aneye condition, such as macular edema or fluid accumulation in the maculaof the eye, treated with the combination of a therapeutic fluid, such asa vasodilator including a non-ambient volume concentration of at leastone of carbon dioxide (CO₂) or nitric oxide (NO) to improve circulationand elimination of fluid from the macula, applied at a gauge pressure inthe cavity 112, such as a positive gauge pressure to apply a compressiveforce to the eye with the therapeutic fluid to reduce macular swelling,can improve the treatment of the eye condition and patient quality oflife.

The enclosure 110 can include a port 116, such as a port 116 located ina surface of the enclosure 110. The port 116 can include a septum, suchas a septum resealable to needle punctures, to allow for theintroduction of instruments into the cavity 112 while maintaining agauge pressure in the cavity 112. In an example, the needle of a syringecan be inserted into or through the septum, such as to place atherapeutic fluid in contact with the eye while maintaining a gaugepressure in the cavity 112.

The enclosure 110 can include a temperature control device, such as tochange the temperature of the therapeutic fluid in the enclosure 110from a first temperature to a second temperature. The enclosuretemperature control device can increase fluid temperature by heating thetherapeutic fluid in the cavity 112, such as to change the vasodilationproperties of the eye or the therapeutic fluid, such as to increasevasodilation in the eye. The therapeutic fluid can be heated in theenclosure 110, such as by conduction using an electrical resistanceheating element in contact with one or more surfaces of the enclosure110. In an example, the electrical resistance heating element can be incontact with the generally concave inner surface of the enclosure 110,the generally convex outer surface of the enclosure 110, or embeddedwithin the enclosure 110, such as between the inner and outer surfacesof the enclosure. The electrical resistance heating element can beelectrically connected to a power source, such as the processor module140 or a wall outlet.

In an example, the apparatus 100 can include a first enclosure 110A anda second enclosure 110B, such as to form a pair of goggles. Enclosures110A and 110B can be joined together by a bridge 119, such as anadjustable bridge that can be fit to a specific patient. The bridge 119can include a pressure tube 117C connected to enclosures 110A and 110B,such as the cavity 112A formed by enclosure 110A can be in fluidiccommunication with the cavity 112B formed by enclosure 110B. In anexample, the fluid pressure in cavity 112A can be the same or about thesame as the fluid pressure in cavity 112B. In an example, the enclosure110 can be sized and shaped to surround two patient eyes where thecavity 112 can be in communication with both eyes simultaneously, suchas in a manner similar to a diving facemask.

The fluid regulator 120 can regulate the flow of fluid between tworeservoirs, such as the fluid flow between a first reservoir at a firstpressure and a second reservoir at a second pressure different from thefirst pressure. The fluid regulator 120 can include a valve, such as toregulate flow rates between the first and second reservoirs. The valvecan include a passive valve, such as a check valve that closes aspressure exceeds a critical value. In an example, a fluid regulator 120Awith a check valve can be located between the enclosure 110A and a fluidsource 170, such as if the pressure of the fluid source 170 exceeds acritical value, such as a pressure that can cause damage to a patienteye, the check valve can close to isolate pressure of the fluid source170 from the patient eye, such as to protect the patient eye fromexcessive force. The valve can include an active valve, such as a servo(or electrically-modulated) valve. In an example, the servo valve canreceive a control signal, such as from the control circuit, to modulatethe position of the servo spool with respect to the valve body, such asto regulate fluid flow through the valve.

The fluid regulator 120 can attach to a fluid source 170, such as toregulate the flow of fluid from the fluid source 170 to the cavity 112.The fluid source 170 can include a storage container, such as a storagecontainer of pressurized therapeutic fluid. A storage container caninclude a disposable or recyclable receptacle, such as a single-usecartridge, or a refillable receptacle, such as a multi-use container orcartridge. The fluid source 170 can include a generator device, such asa device that concentrates or distills a therapeutic fluid from anotherfluid. In an example, a generator device can include a concentrator,such as an oxygen concentrator or a carbon dioxide concentrator. In anexample, a generator device can include an atomizer, such as anultrasonic humidifier or an aerosolizer, to transform a therapeuticliquid, such as an miscible solution or colloidal suspension, into atherapeutic gas, such as a therapeutic mist or fog,

The fluid regulator 120 can be connected to the apparatus 100, such asto place the output of the fluid regulator 120 in communication with thecavity 112. In an example, the fluid regulator 120A can be connected tothe enclosure 110A, such as with the pressure tube 117D in directcommunication with the enclosure 110A. In an example, the fluidregulator 120B can be connected to the pressure tube 117B incommunication with the enclosure 110B by a tube connector 118, such as aY-connector. In an example, the fluid regulator 120C can be connected tothe processor module 140, such as to be in communication with theenclosure 110A by the pressure tube 117A connected to the processormodule 140.

An indication of the eye can include a characteristic of the eye, suchas a physical characteristic, that can vary over time, such as due tophysiological changes in the eye or in response to a therapy applied tothe eye. A physical characteristic of the eye can include at least oneof an intraocular pressure (or IOP), a translaminar pressure difference(or TPD), a cup-to-disc ratio, a caliber of a blood vessel in the eye,such as a change in the caliber of the blood vessel, or displacement ofthe lamina cribrosa, such as a change in the displacement of the laminacribrosa.

An indication of the environment, such as the therapeutic environment inthe cavity 112, can include a characteristic of the therapeutic fluid. Acharacteristic of the therapeutic fluid can include at least one oftherapeutic fluid flow, such as in the cavity 112, humidity, pressure,temperature, gas, such as gas composition or partial pressure fraction,or biomarkers, such as bodily substances released from the eye into thecavity 112.

The sensor 130 can sense an indication, such as an indication of the eyeand an indication of the therapeutic environment. Sensing an indicationof the eye, such as a change in an indication of an eye, can quantifythe progression of an eye condition and the effectiveness of an appliedtreatment. In an example, a characteristic of the eye, such as thecup-to-disc ratio, can change due to an eye condition, such as a changefrom a first cup-to-disc ratio at a first IOP to a second cup-to-discratio at a second IOP greater than the first IOP can suggest thepresence of glaucoma. Applied therapies to treat the eye condition canalso change the indication of the eye, such as a glaucoma therapyapplied to the eye can change the second cup-to-disc ratio to the firstcup-to-disc ratio, such as by lowering IOP in the eye.

A physical characteristic of the eye can be sensed with the sensor 130.The sensor 130 can include a human eye, such as in combination with aslit lamp, such as with or without magnification, an imaging device,such as a digital camera, an optical coherence tomography (OCT) imagingsystem, or a blood vessel characteristic detector, such as the detectorsand methods described in the U.S. Patent Application No. 62/210,751 byBerdahl, filed on Aug. 27, 2015 which is incorporated herein byreference in its entirety.

The sensor 130 can be located outside the eye, such as in proximity tobut apart from the apparatus 100. In an example, the sensor 130, such asthe OCT imaging system, can be used to detect a first position of thelamina cribrosa subject to a first condition of the eye, such as a firstintraocular pressure (TOP), and a second position of the lamina cribrosasubject to a second condition of the eye, such as a second IOP. In anexample, the sensor 130, such as a blood vessel characteristic detector,can be used to detect a characteristic of a blood vessel, such as afirst caliber of an episcleral blood vessel subject to a first IOP, anda second caliber of the episcleral blood vessel subject to a second IOP.The OCT and blood vessel characteristic detector can be located in anoffice, such as the office of a medical professional, for use duringperiodic eye exams, such as to document the progression of a chronic eyecondition and suggest treatment regimens to address the eye condition.

The sensor 130 can be located inside the eye, such as within theintraocular space of the eye. The sensor 130 can include a device thatcan detect pressure, such as the IOP of the eye implanted with thesensor 130. The sensor 130 can be located within the intraocular spaceof the eye to detect a first IOP of the eye subject to a first conditionof the eye, and a second IOP of the eye subject to a second condition ofthe eye, such as to determine the effect of a gaseous therapy treatmentdelivered by the apparatus 100 to the eye. In an example, the sensor 130can include a sensor system, such as the detectors and methods describedin the U.S. patent application Ser. No. 13/818,497 by Ostermeier, filedon Feb. 22, 2013 which is incorporated herein by reference in itsentirety and the WIT eye pressure measurement system from ImplandataOphthalmic Products GmbH (Hannover, Germany) described in thepublication “An Implantable Intraocular Pressure Transducer InitialSafety Outcomes”, by Melki, et at., JAMA Ophthalmology, published onlineJun. 26, 2014, and incorporated herein by reference in its entirety. Thesensor 130 located in the eye can provide continuous sensing of anindication of the eye, such as IOP, for use during treatment of the eyecondition, such as with the apparatus 100, to vary the therapeuticenvironment, such as the composition and pressure of the therapeuticfluid, with a controller, such as a closed loop controller, to improvepatient treatment.

The sensor 130 can sense an indication of the therapeutic environment inthe cavity 112, such as a characteristic of the therapeutic fluid incontact with the eye, such as at least one of therapeutic fluid flow,humidity, pressure, temperature, or medicinal fluid concentration. Thesensor 130 can be located in proximity to the apparatus 100, such as incommunication with the cavity 112, and can provide continuous sensing ofthe therapeutic fluid, such as for use as a feedback parameter in aclosed-loop control system. The indication of the therapeuticenvironment can be received by the processing module 140, such as by aPID controller, to control the composition and pressure of thetherapeutic fluid in the cavity 112, such as adhere to a therapy regimenprescribed by a medical professional to treat an eye condition.

The sensor 130 can include a flow sensor, such as a device to sense anindication of the flow of the therapeutic fluid introduced into thecavity 112. The sensor 130 can include a humidity sensor, such as adevice to sense an indication of the relative humidity of thetherapeutic fluid in the cavity 112. The sensor 130 can include apressure sensor, such as a device to sense an indication of the pressureof the therapeutic fluid in the cavity 112. The sensor 130 can include athermometer, such as a device to sense an indication of the temperatureof the therapeutic fluid in the cavity 112.

The sensor 130 can include a gas sensor, such as a device to sense anindication of a gaseous substance in the therapeutic fluid, such as apercent concentration of the gaseous substance in the therapeutic fluid.In an example, the gaseous substance can include a medicinal gas, suchas a constituent of the therapeutic fluid delivered to the cavity 112.In an example, the gaseous substance can include a biomarker, such as abiomarker emitted by the eye.

A biomarker can include ketones, such as can be detected with a volatilegas sensor including a quartz crystal nanobalance (QCN) sensor, glucose,such as can be detected with an optical glucose sensor including an OCTimaging system, oxygen levels, such as can be detected with anon-invasive optical oxygen sensor, dissolved salts, such as can bedetected with a salinity sensor, and vascular endothelial growth factor(or VEGF), such as can be detected with an aptamer-based sensorincluding the sensor and methods described in the publication “FlexibleFET-Type VEGF Aptasensor Based on Nitrogen-Doped Graphene Converted fromConducting Polymer”, by Kwon, et at., ACS Nano, Vol. 6, #2, pages1486-1493, published February 2012, and incorporated herein by referencein its entirety. Biomarkers can suggest a physiological state of theeye, such as a state of stability or a state of distress, such as wheremedical intervention can be required.

The sensor 130 can include a pulse oximeter device, such as a device tosense an indication of systemic oxygen levels. In an example, theindication of systemic oxygen levels can be received by the processingmodule 140 and oxygen concentration in the therapeutic fluid adjusted,such as increased, to maintain oxygenation of the eye even in thepresence of low systemic oxygen levels.

The processor module 140 can provide a communication interface, such asto allow a user to operate the apparatus 100. The communicationinterface can include an operations unit, such as for a user to managebasic functionality of the apparatus 100, such as cycling the power ofthe apparatus 100. The communication interface can include a dataacquisition unit to record an indication, such as an indication of thetherapeutic fluid in the cavity 112 or an indication of the eye, over aperiod of time. In an example, the indication can be recorded for arelatively short period of time, such as for health screening purposes,or for a relatively long period of time, such as for monitoring theeffect of a prescribed treatment on the eye condition treated.

The processor module 140 can control the operation of the apparatus 100,such as the apparatus can operate in a feedback or closed-loop controlmode. The processor module 140 can be in communication, such aselectrical communication, with at least one of the regulator 120, thesensor 130, or the pump 150, such as to coordinate operation of thecomponents. The processor module 140 can receive a signal, such as asignal proportional to an indication of the eye or the environment, fromthe sensor 130 and process the signal, such as to compare a first signalto a second signal, such as to find a difference between the first andsecond signals. The processor module 140 can include a control circuit,such as to implement a control algorithm including a feedback controlalgorithm. In an example, the control circuit can include a controller,such as a proportional-integral-derivative (or PID) controller. Inoperation, the control circuit can receive a signal from the sensor 130,such as an electrical signal proportional to changes in the sensedindication, process the signal, such as with a PID controller tominimize a steady state error between the sensor signal and a set point,such as a specified user-defined set point, and generate a controlsignal, such as to adjust the operational state of at least one of theregulator 120, a manifold vent 144, or the pump 150.

The processor module 140 can include a power source, such as to supplyelectrical energy to the apparatus 100. In an example, the power sourcecan include a battery, such as a lithium ion battery, and a transformer,such as to receive power from a wall outlet for use in the apparatus 100at a specified voltage and current. The processor module 140 can includea heating element, such as a heating element in communication with thetherapeutic fluid including a heating element located on a surface ofthe mixing chamber 146, to increase the temperature of the therapeuticfluid.

FIG. 1B shows an example of a manifold 149, such as a manifold 149 thatcan be in communication with the processing module 140, such as inelectrical communication, and the pump 150, such as in fluidiccommunication. The manifold can include a mixing chamber 146, such as tofluidically connect the fluid regulator 120C and the pump outlet 155with the pressure tube 117, such as the pressure tube 117A. Inoperation, volumetric fluid flow from the pump outlet 155 can combinewith a medicinal fluid, such as from the fluid source 170 via the fluidregulator 120C, to form a therapeutic fluid in the mixing chamber 146.The therapeutic fluid can exit the mixing chamber 146 through thepressure tube 117A, such as for introduction into the cavity 112A.

The manifold 149 can include an inlet chamber 148, such as tofluidically connect the pump inlet 156 with the pressure tube 117, suchas pressure tube 117B in fluidic communication with the cavity 112B, andthe manifold vent 144, such as in communication with the ambientenvironment.

The manifold 149 can include a vent 144 in fluid communication with thecavity 112, such as to adjust the gauge pressure within the enclosure110. The vent 144 can communicate with the processor module 140 to openand close the vent 144, such as to maintain a desired gauge pressurewithin the cavity 112. In an example, as a gauge pressure sensed by asensor 130 in the cavity 112 exceeds a predetermined threshold value,the vent 144 can receive a control signal from the control circuit, suchas to modulate the vent 144 to maintain a desired gauge pressure withinthe cavity 112.

In operation, the pump 150 can create a region of low pressure at thepump inlet 156, such as to draw therapeutic fluid from the pressure tube117B and ambient fluid, such as air at standard temperature andpressure, from the manifold vent 144. The composition of the therapeuticfluid can be adjusted by the amount of ambient air drawn from themanifold vent 144.

The pump 150 can generate a volumetric fluid flow, such as by usingfluid from the apparatus 100, such as the cavity 112, or from anexternal source. The pump 150 can include a passage 157, such as betweenthe pump inlet 156 and the pump outlet 155, and a fan 153 located atleast partially in the passage 157, such as a centrifugal fan capable ofgenerating a volumetric fluid flow. The pump 150 can include a filter158, such as a particulate filter to remove dust and a desiccant filterto remove water vapor (i.e., humidity) from fluid flow in communicationwith the passage 157, and a pump vent 159 in communication with thepassage 157 and the surrounding environment, such as to allow for theintroduction of ambient air into the apparatus 100. The pump 150 caninclude a power source 152, such as a battery, and be in communicationwith the enclosure 120, the sensor 130, and the processor module 140.

In operation, rotation of the fan 153 in the passage 157 can draw fluidfrom an inlet, such as from the pump inlet 156 including the vent 144and the pump vent 159, to generate a volumetric fluid flow at an outlet,such as the pump outlet 155. The filter 158 can be located in thepassage 157, such as between the pump inlet 156 and the fan 153 or thefan 153 and the pump outlet 155. Exposure of the filter 158 to the fluidflow can be regulated, such as the volume of fluid flow passing throughthe filter can be controlled, such as to adjust a parameter of thetherapeutic fluid. In an example, the humidity in the therapeutic fluidcan be adjusted, such as decreased, by exposing at least a portion ofthe therapeutic fluid to the filter 158, such as a desiccant filter.Exposure of the filter 158 to the therapeutic fluid can be regulatedwith a slide valve, such as a slide valve attached to an actuator and inelectrical communication with the control circuit of the processingmodule 140. In an example, water vapor can be entrained in the desiccantfilter, such as until the desiccant filter can be saturated, andthereafter eliminated from the apparatus 100, such as by replacing thesaturated desiccant filter 158 or by heating the desiccant filter 158,such as to cause the water vapor to evaporate from the desiccant filter158.

The pump 150 can apply and maintain a gauge pressure in the cavity 112and distribute fluid, such as therapeutic fluid, in the cavity 112. Theapplied gauge pressures can vary in a range from about −40 mmHg to about40 mmHg, such as in a range from about −20 mmHg to about 20 mmHg, in arange of about −10 mmHg to about 10 mmHg, in a range of about −5 mmHg toabout 5 mmHg, in a range of about −1 mmHg to about 1 mmHg, or in a rangeof about −0.5 mmHg to about 0.5 mmHg. In an example, the pump 150 canapply a gauge pressure to the cavity 112 at a level of at least one of−40 mmHg, −35 mmHg, −30 mmHg, −25 mmHg, −20 mmHg, −15 mmHg, −10 mmHg, −5mmHg, −4 mmHg, −3 mmHg, −2 mmHg, −1 mmHg, −0.9 mmHg, −0.8 mmHg, −0.7mmHg, −0.6 mmHg, −0.5 mmHg −0.4 mmHg, −0.3 mmHg, −0.2 mmHg, −0.1 mmHg,−0.09 mmHg, −0.08 mmHg, −0.07 mmHg, −0.06 mmHg, −0.05 mmHg, −0.04 mmHg,−0.03 mmHg, −0.02 mmHg, −0.01 mmHg, 0.01 mmHg, 0.02 mmHg, 0.03 mmHg,0.04 mmHg, 0.05 mmHg, 0.06 mmHg, 0.07 mmHg, 0.08 mmHg, 0.09 mmHg, 0.1mmHg, 0.2 mmHg, 0.3 mmHg, 0.4 mmHg, 0.5 mmHg, 0.6 mmHg, 0.7 mmHg, 0.8mmHg, 0.9 mmHg, 1 mmHg, 2 mmHg, 3 mmHg, 4 mmHg, 5 mmHg, 10 mmHg, 15mmHg, 20 mmHg, 25 mmHg, 30 mmHg, 35 mmHg, or 40 mmHg.

The appropriate duration to apply therapeutic fluids, such as atherapeutic fluid applied with or without a gauge pressure, can varydepending on the eye condition treated. A therapeutic regimen for anacute eye condition can require application of a therapeutic fluid, suchas with or without gauge pressure, for relatively short periods of time,such as for periods of time measured in minutes, hours, days, or weeks.In an example, a therapeutic regimen to treat an acute eye condition caninclude application of a therapeutic fluid with the apparatus 100 for atleast one of 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21hours, 22 hours, 23 hours, and 24 hours, 1 day, 2 days, 3 days, 4 days,5 days, 6 days, and 7 days, 1 week, 2 weeks, 3 weeks, or 4 weeks.

Therapeutic regimens for chronic eye conditions, such as glaucoma, canrequire application of a therapeutic fluid, such as with or withoutgauge pressure, for relatively long periods of time, such as for periodsof time measured in days, weeks, months or years. In an example, atherapeutic regimen to treat a chronic eye condition can includeapplication of a therapeutic fluid with the apparatus 100 for at leastone of 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, and 7 days, 1week, 2 weeks, 3 weeks, and 4 weeks, 1 month, 2 months, 3 months, 4months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11months, and 12 months, 1 year, 2 years, 3 years, 4 years, 5 years, 6years, 7 years, 8 years, 9 years, or 10 years. In an example, atherapeutic regimen to treat a chronic eye condition, such as glaucomaand optic disc edema, can include the application of a therapeuticfluid, such as with or without gauge pressure, delivered to the eye withthe apparatus 100 for the lifetime of the patient.

The pump 150 can modulate the therapeutic fluid, such as with or withoutgauge pressure, applied to the cavity 112, such as periodically andaperiodically. A periodic gauge pressure can include a gauge pressurethat can vary in magnitude at regular intervals, such as with sinusoidalsignals, periodic non-sinusoidal signals, and repeating processes. In anexample, the gauge pressure applied to the enclosure 110 can vary in asubstantially sinusoidal fashion with a period of approximately24-hours, such as to compensate for the natural diurnal cycle of IOP inthe eye of the patient. A periodic gauge pressure can include gaugepressures that vary in frequency, such as the time between repeatingintervals in the periodic signal. In an example, the gauge pressureapplied to the enclosure can vary in frequency, such as when the gaugepressure applied to the cavity 112 can vary as a function of cardiacactivity, such as heart rate and blood pressure, the cardiac activitymeasured by a detection device, such as a blood pressure monitoringdevice in communication with the processing module 140.

An aperiodic gauge pressure can include gauge pressures that vary inmagnitude at irregular intervals, such as non-periodic signals andnon-repeating processes. The gauge pressure applied to the enclosure canvary in an aperiodic fashion that is dependent upon an indication of abody parameter, such as the position of a patient with respect to acoordinate system. In an example, an indication of a body position caninclude a change in body position, such as the change in body positionof a patient transitioning from a first body position, such as astanding position, to a second body position, such as a sitting or proneposition. The gauge pressure applied to the enclosure 110 can vary in anaperiodic fashion that is dependent upon the summation of one or moreperiodic and aperiodic signals. In an example, the gauge pressureapplied to the enclosure 110 can include a periodic component, such asthe gauge pressure due to cardiac activity, and an aperiodic components,such as the gauge pressure due to the body position of a patient.

FIG. 5 shows an example method 500 for introducing a fluid, such as agaseous therapeutic fluid other than ambient air, into a cavity 112. At502, an enclosure 110 can be provided, such as an enclosure 110 sizedand shaped to be seated about an eye, such as to form a cavity 112within the enclosure 110 over the eye. The enclosure 110 can include agasket 114 that can be seated between the enclosure 110 and the skin ofthe patient to form a seal between the enclosure 110 and the skin of thepatient. The gasket 114 can be selected to form a resistance flow pathbetween the therapeutic environment within the cavity 112 and thesurrounding environment, such as the resistance can be dependent uponthe gasket used. In an example, the gasket 114 can form a ‘loose’ sealbetween the enclosure 110 and the patient, such as to allow some leakageof fluid from the cavity 112 through the resistance flow path to thesurrounding environment, such as to maintain a slight gauge pressure inthe cavity 112. In an example, the gasket 114 can form a ‘tight’ sealbetween the enclosure 110 and the patient, such as to largely preventleakage of fluid from the cavity 112 through the resistance flow path tothe surrounding environment, such as to maintain a substantial gaugepressure in the cavity 112. In an example, the gasket 114 can form ahermetic seal that can prevent leakage of fluid from the cavity 112 tothe surrounding environment.

At 504, a fluid, such as therapeutic fluid other than ambient air, canbe provided to the cavity 112. The therapeutic fluid can includemedicinal fluids, such as pure gases including nitric oxide and carbondioxide, and combinations of medicinal gases. In an example, acombination of medicinal gases can include a combination of nitric oxideand carbon dioxide, such as to affect vasodilation of an eye byincreasing aqueous humor outflow to lower TOP. The percentage of nitricoxide and carbon dioxide can be specified to achieve a specificendpoint, such as to maximize vasodilation of an eye based on thephysiology of a specific patient. The percentage of nitric oxide caninclude specified percentages of nitric oxide, such as 1%, 2%, 3%, 5%,10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%,80%, 85%, 90%, 95%, 96%, 97%, 98% 99%, or other percentages.

In an example, a combination of gases can include a combination ofnitric oxide and oxygen, such as to provide increased oxygenconcentration to tissues, such as eye tissues, while increasingvasodilation of an eye, such as by increasing aqueous humor outflow tolower TOP. The percentage of nitric oxide and oxygen can be specified toachieve a specific endpoint, such as to maximize eye tissue oxygensaturation based on the physiology of a specific patient.

The gaseous therapeutic fluid can include water vapor, such as humidity.The humidity of the therapeutic fluid can include a specified humidity,such as a specified percentage humidity (e.g., relative humidity), suchas 1%, 2%, 3%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%,60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% 99%, or otherpercentages.

The therapeutic fluid provided to the cavity 112 can be in contact withthe eye, such as the anterior surface of the eye including the corneal,scleral, and conjunctival surfaces of the eye, so that the therapeuticfluids can pass into the eye, such as through absorption of thetherapeutic fluid through the surfaces of the eye. The composition ofthe therapeutic fluid can be controlled, such as with a fluid regulator120. The fluid regulator 120 can include a passive valve, such as acheck valve that closes as pressure exceeds a critical value, such as apressure that can damage a patient eye. In an example, where thepressure of the fluid source 170 can be less than the critical value,fluid can flow between the cavity 112 and the fluid source 170. In anexample, where the pressure of the fluid source 170 can be equal to orgreater than the critical value, the check valve can close, such as toprevent damage to the patient eye. In an example, the critical value canbe adjusted, such as the check valve can be adjusted from a firstcritical value to a second critical value, such as a second criticalvalue different from the first critical value.

FIG. 6 shows an example method 600 of sensing an indication with theapparatus 100. At 606, an indication of the eye or an indication of theenvironment in the cavity 112 can be sensed, such as with a sensor 130.Sensing an indication of the eye can include sensing a physicalcharacteristic of the eye, such as a change in a physicalcharacteristic. The physical characteristic can be sensed periodically,such as to track progression of an eye condition as a part of an eyeexam, or continuously, such as a feedback parameter in a closed-loopcontrol system configured to adjust the composition of the therapeuticfluid in the cavity 112.

Sensing an indication of the environment can include sensing acharacteristic of the therapeutic fluid in the cavity 112, such as thelevel of the characteristic or a change in the level of thecharacteristic. In an example, the sensor 130 can sense a level of fluidconcentration or a change in fluid concentration, such as theconcentration of a medicinal fluid in the therapeutic fluid. Thetherapeutic fluid characteristic can be sensed periodically, such as ona daily or hourly schedule, or continuously.

FIG. 7 shows an example method 700 for adjusting a therapeutic fluidwithin the cavity 112. At 708, the therapeutic fluid, such as thecomposition of the therapeutic fluid, can be varied. Varying thetherapeutic fluid can include changing the composition of thetherapeutic fluid, such as by varying the concentration of a constituentfluid, such as a medicinal gas, within the therapeutic fluid.

Varying the composition of the therapeutic fluid can include manuallyadjusting the concentration of a constituent fluid, such as by adjustinga valve on the fluid regulator 120. In an example, upon recognizingworsening symptoms of an eye condition an eye patient can vary thecomposition of the therapeutic fluid provided to the cavity 112, such asby increasing the flow of medicinal fluid to the cavity 112, such as bymanually opening the check valve of a fluid regulator 120, until thesymptoms of the eye condition dissipate.

Varying the composition of the therapeutic fluid can include operatingthe apparatus 100 with an open-loop control algorithm, such as with acontroller varying therapeutic composition at predetermined times. Eyepressure of a patient can vary throughout the day, such as IOP can beelevated during the active hours of the day and lowered during theinactive hours. In an example, the apparatus 100 can manage IOP therapy,such as with a control circuit operating an open-loop algorithm wherethe control circuit can be connected to a servo valve, the controlcircuit programmed to initiate a preset pattern based on time of theday. For example, the control circuit can adjust the servo valve of afluid regulator 120 to increase oxygen concentration in the therapeuticfluid during hours when the patient can be active and decrease oxygenconcentration in the therapeutic fluid during hours when the patient canbe inactive.

Varying the composition of the therapeutic fluid can include operatingthe apparatus 100 with a closed-loop control algorithm, such as with acontroller varying therapeutic composition in response to receiving afirst feedback parameter, such as an indication of the eye. In anexample, a sensor 130, such as a digital camera, can sense a change inan indication of the eye, such as a change in the cup-to-disc ratio ofthe eye. The digital camera can sense a change in cup-to-disc ratio,such as by comparison of a first image captured at a first time instanceand a second image captured at a second time instance and identifyingthe difference between the first and second images, such as with theprocessing module 140. A controller, such as a PID controller, canreceive a signal from the sensor 130 proportional to the indication ofthe eye and issue a control signal, such as to the fluid regulator 120,to vary the composition of medicinal fluid, such as to counteract thechange in the cup-to-disc ratio sensed by the sensor 130.

Varying the composition of the therapeutic fluid can include receiving asecond feedback parameter, such as an indication of the environment inthe cavity 112. In an example, a sensor 130, such as a gas sensor, cansense an indication of the therapeutic fluid, such as the concentrationof a medicinal fluid. A controller can receive a signal from the sensor130 proportional to the indication of the therapeutic fluid and comparethe received signal to a set point value. Where the concentration of themedicinal fluid falls below the set point value, the controller canissue a control signal to the fluid regulator 120 to vary the fluid flowof a medicinal fluid from the fluid source 170, such as to increasemedicinal fluid concentration in the therapeutic fluid and minimize thedifference in the received signal and the set point value. Where theconcentration of the medicinal fluid exceeds the set point value, thecontroller can issue a control signal to the pump 150, such as the fan153, to increase volumetric fluid flow, such as to decrease or dilutemedicinal fluid concentration in the therapeutic fluid and minimize thedifference in the received signal and the set point value.

FIG. 8 shows an example method 800 for receiving a patient. At 810,receiving a patient can include receiving a patient with an eyecondition for treatment with the therapeutic fluid.

Eye conditions including glaucoma, dry eye, diabetic retinopathy,cataract, venous and arterial occlusive diseases, macular degeneration,diseases of the cornea, endothelium, and epithelium, diseases of theretinal vasculature, diseases of the retinal pigmented epithelium,corneal infections, or other infections of the eye can be treated with atherapeutic fluid, the therapeutic fluid including a medicinal fluid,such as at least one of carbon dioxide, oxygen, or nitric oxide. Thespecified non-ambient concentration of medicinal fluid in thetherapeutic fluid can include a percentage concentration, such as 1%,2%, 3%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%,70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% 99%, or other percentages.In an example, the therapeutic fluid can include between 50 percent and80 percent carbon dioxide (CO₂), such as to treat glaucoma. In anexample, the therapeutic fluid can include between 50 percent and 95percent oxygen (O₂), such as to treat diabetes or Fuchs' dystrophy. Inan example, the therapeutic fluid can include between 10 percent and 90percent nitric oxide (NO), such as to treat glaucoma.

The example method 800 can be used to treat an eye, such as topotentiate a therapeutic substance in contact with the eye. Potentiationcan be described as the interaction between two or more therapeuticagents that results in a pharmacologic response greater than the sum ofresponses to each agent individually. A first potentiating therapeuticagent can include a therapeutic fluid, such as at least one ofriboflavin, decorin, anti-VEGF, antibiotics, antiviral, or antifungalfluids. A second potentiating therapeutic agent can include a source ofradiating energy, such as at least one of incoherent light, infrared(IR) light, ultraviolet (UV) light, coherent light, such as realizedwith a laser, or a medicinal fluid.

In an example, the method 800 can potentiate a first set of therapeuticagents, such as to treat corneal ectasia including keratoconus, pellucidmarginal degeneration (PMD), and post-LASIK ectasia, by corneal collagencross-linking. At 810, a patient suffering from corneal ectasia can bereceived. At 502, an enclosure sized and shaped to seat about an eye canform a cavity 112 over the eye. At 504, a first potentiating therapeuticagent, such as a gaseous fluid other than ambient air including a fluidwith a specified concentration of riboflavin, and a second potentiatingtherapeutic agent, such as radiation energy including UV-A light, can beintroduced into the cavity 112. Gaseous riboflavin can be absorbed intothe anterior surface of the eye and exposure to UV-A light, such asexposure through the enclosure 110 irradiating the eye and theriboflavin-rich therapeutic fluid, can potentiate the absorbedriboflavin, such as to form additional bonds between adjacent collagenstrands in the stromal layer of the cornea, to improve the strength andelasticity of the cornea. At 606, an indication of the concentration ofriboflavin can be sensed in the cavity 112, such as to indicate theamount of riboflavin absorbed by the eye. At 708, the concentration ofriboflavin can be varied, such as increased or decreased, such as to aphysician-recommended concentration.

In an example, the method 800 can potentiate a second set of therapeuticagents, such as a third therapeutic agent including a specifiedconcentration of decorin and a fourth therapeutic agent including aspecified concentration of oxygen, in the same manner as the first setof therapeutic agents.

The example method 800 can be used to treat an eye, such as to inhibitinfections of the eye. An aerobic infection involves the growth ofbacteria requiring free oxygen whereas an anaerobic infection involvesthe growth of bacteria in the absence of free oxygen.

In an example, the method of 800 can inhibit the growth of infections ofthe eye, such as by providing an oxygen-deprived environment to stiflegrowth of an aerobic infection or an oxygen-rich environment to suppressthe growth of an anaerobic infection. At 810, a patient suffering froman eye infection, such as an aerobic or an anaerobic infection, can bereceived. At 502, an enclosure sized and shaped to seat about an eye canform a cavity 112 over the eye. At 504, a therapeutic fluid other thanambient air, such as a nitrogen-rich environment including a therapeuticfluid composed of more than 78% nitrogen to treat aerobic infections andan oxygen-rich environment including a therapeutic fluid composed ofmore than 21% oxygen to treat anaerobic infections, can be provided tothe cavity 112. At 606, an indication of the environment, such as theconcentration of a fluid other than ambient air can be sensed in thecavity 112, such as to assess the potency of the infection treatment. At708, the concentration of a fluid other than ambient air can be varied,such as increased or decreased, such as to a physician-recommendedconcentration to treat the eye infection.

The example method 800 can be used to treat an eye, such as minimizepost-operative damage during the healing process of the eye. In anexample, a hypoxic (or oxygen-deprived) environment can reduce cornealscarring and hazing in recuperation of the eye. The method used to treatan infection, such as an aerobic infection as disclosed above, can beused to minimize eye scarring and hazing.

FIG. 9 shows an example method 900 of a treatment for Fuchs' dystrophy.Fuchs' dystrophy can occur when the cornea swells, such as due toendothelial cell dysfunction. Fuchs' dystrophy can be treated byreducing the IOP of the eye and by removing water from the cornea, suchas through the application of dehydrating agents including sodiumchloride and glycerin to the surface of the eye and evaporation of waterfrom the surface of the eye.

At 902, a patient with an eye condition, such as Fuchs' dystrophy, canbe received. At 904, an enclosure 110 can be provided to fit over theeye of the patient, such as to form the cavity 112 between the patienteye and the enclosure 110. At 906, a therapeutic fluid other thanambient air can be provided to the cavity 112, such as to allow thetherapeutic fluid to contact the surface of the patient eye. In anexample, the therapeutic fluid can include a composition of medicinalfluids, such as a therapeutic fluid with a specified non-ambientconcentration of at least one of carbon dioxide (CO₂), oxygen (O₂),nitric oxide (NO), or water vapor, such as with water vapor in an amountsufficient to realize a desired relative humidity of the composition ofgaseous fluids. The specified non-ambient concentration of a constituentof the therapeutic fluid, such as oxygen or relative humidity, caninclude a percentage concentration, such as 1%, 2%, 3%, 5%, 10%, 15%,20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%,90%, 95%, 96%, 97%, 98% 99%, or other percentages. The percentageconcentration of the constituent can be selected for a therapeuticpurpose. In an example, the gaseous fluid can include between 30 percentand 100 percent oxygen (O₂), such as to maintain or improve endothelialcell function in those diagnosed with Fuchs' dystrophy. The treatment ofFuchs' dystrophy, such as the example method 900, can be extended topatients with symptoms similar to Fuchs' dystrophy. In an example, thetherapeutic fluid, such as a gaseous fluid including between 30 percentand 100 percent oxygen, can be used to maintain or improve endothelialcell function in people exposed to a high altitude or low oxygenenvironments, such as astronomers, astronauts, hikers, or others. At908, at least one of a first sensor 130, such as an OCT imaging system,can sense an indication of the eye, such as a change in the deflectionof the lamina cribrosa to estimate IOP, or a second sensor 130, such asa humidity sensor, can sense an indication of the environment, such asthe relative humidity within the cavity 112, to monitor the effect ofthe therapeutic fluid on the patient eye. At 910, the composition of thetherapeutic fluid, such as the constituents of the therapeutic fluid andthe level of relative humidity, can be varied, such as by adjusting thespecified non-ambient concentration of at least one of the constituentsof the therapeutic fluid or adjusting the relative humidity, such as toimprove the treatment for Fuchs' dystrophy as applied to the patienteye.

FIG. 10 shows an example method 1000 to introduce gaseous fluids, suchas gaseous fluids other than ambient air, into the cavity 112 with apositive gauge pressure. In an example, a user can interact with theoperations unit of the processor module 140, such as to initiateoperation of the method 1000.

At 1002, the vent 144 can be opened. Opening the vent 144 can equalizefluid pressure in the apparatus 100, such as in the cavity 112, with thesurrounding environment. Equalizing pressure can prepare the cavity 112to receive a specified gaseous fluid, such as a therapeutic fluid.

At 1004, fluid regulator 120, such as a valve of the fluid regulator120C, can be opened. Opening the valve of the fluid regulator 120C canallow a fluid, such as a medicinal fluid, to flow out of the fluidsource 170 into the processor module 140, such as into a mixing chamber146 in communication with the pressure tube 117 and the pump outlet 155.In an example, the composition of the therapeutic fluid can be adjusted,such as by changing the outflow rate of the fluid source, such as byopening and closing the valve of the fluid regulator 120C. In anexample, the valve can be opened at a predetermined rate, such as inresponse to a control signal from the processor module 140, to graduallyincrease the concentration of medicinal fluid released into the mixingchamber 146 over time.

At 1006, the pump 150 can be started to generate volumetric fluid flow,such as to generate a positive gauge pressure at the pump outlet 155. Inan example, the pump inlet 156 can be blocked, and the pump outlet 155can be in direct communication with the mixing chamber 146, such as thevolume output can combine with the medicinal fluid flowing through thefluid regulator 120C, such as to create a therapeutic fluid. Thecomposition of the therapeutic fluid can depend on the volume output ofthe pump 150 and on the volume and concentration of the medicinal fluidflowing through the fluid regulator 120C. In an example, the compositionof the therapeutic fluid can be adjusted, such as by changing the volumeoutput of the pump 150. For example, the volume output of the pump 150can be changed by increasing or decreasing the speed of the pump 150,such as the fan 153 of a centrifugal pump. The therapeutic fluid canflow out of the mixing chamber 146, such as through the pressure tube117 into the cavity 112.

At 1008, a sensor 130, such as a gas sensor located in the cavity 112,can sense the therapeutic fluid flowing into the cavity 112, such as tosense an indication of the concentration of medicinal fluid in thetherapeutic fluid. The processor module 140 can receive a signal fromthe sensor 130, such as an electrical signal proportional to theindication of the concentration of medicinal fluid in the therapeuticfluid. The received sensor signal can be compared to a predetermined setpoint value, such as a physician-recommended concentration of medicinalfluid for the treatment of an eye condition, with the control circuit.If the received sensor signal is less than the predeterminedconcentration set point value, the valve of the fluid regulator 120C canbe further opened at 1007, such as to increase the concentration ofmedicinal fluid in the mixing chamber 146, and the therapeutic fluid canbe re-sensed at 1008. The valve of the fluid regulator 120C can continueto open until the received sensor signal, such as sensed in the cavity112, reaches the predetermined concentration set point value.

At 1010, the vent 144 can be closed. After the received sensor signalmeets the predetermined set point value, the therapeutic fluid can beconsidered adequately mixed in the apparatus 100 at the pressure of thesurrounding environment, such as the local ambient pressure. The vent144 can then be closed, such as to allow the pump 150 to build positivegauge pressure in the apparatus 100.

At 1012, a sensor 130, such as a pressure sensor located in the cavity112, can sense the fluid pressure in the cavity 112, such as for anindication of therapeutic fluid gauge pressure. The processor module 140can receive a signal from the sensor 130, such as an electrical signalproportional to the gauge pressure of the therapeutic fluid. Thereceived sensor signal can be compared to a predetermined set pointvalue, such as a physician-recommended gauge pressure of the therapeuticfluid for the treatment of an eye condition, with the control circuit.If the received sensor signal is less than the predetermined gaugepressure set point value, the speed of the fan 153 can be increased at711, such as to increase the volumetric fluid flow in the mixing chamber146, and the therapeutic fluid can be re-sensed at 1013. The pump 150can continue to generate volumetric fluid flow until the gauge pressure,such as sensed in the cavity 112, reaches the predetermined gaugepressure set point value.

At 1014, the pump can be stopped, such as upon achieving thepredetermined gauge pressure set point value. Stopping the pump 150 canprevent changes in composition of the therapeutic fluid, such as inmedicinal fluid concentration and gauge pressure.

At 1016, the valve in the fluid regulator 120C can be closed. Closingthe valve of the fluid regulator 120C can stop the medicinal fluid fromflowing out of the fluid source 170. In an example, the valve can beclosed at a predetermined rate, such as a rate selected to preventconcentration changes in the therapeutic fluid.

At 1018, the sensor 130 can sense an indication of the therapeutic fluidin the cavity 112, such as for deviation from a specified set pointvalue. In an example, an indication of the concentration of medicinalfluid in the therapeutic fluid can be sensed by the gas sensor andcompared to the physician-recommended concentration set point level withthe control circuit, such as to a tolerance range (or error band)centered around the set point level. In an example, an indication of thepositive gauge pressure of the therapeutic fluid can be sensed by thepressure sensor and compared to the physician-recommended positive gaugepressure set point level with the control circuit, such as to atolerance range (or error band) centered around the set point level.When the sensed indication falls outside the tolerance range, the methodof 1000 can be reinitiated, such as at 1004, to adjust the sensedindication to a value within the tolerance range.

FIG. 11 shows an example method 1100 to introduce gaseous fluids, suchas gaseous fluids other than ambient air, into the cavity 112 with anegative gauge pressure. In an example, a user can interact with theoperations unit of the processor module 140, such as to initiateoperation of the method 1100.

At 1102, the vent 144 can be closed. Closing the vent 144 can isolatefluid pressure in the apparatus 100, such as in the cavity 112, from thesurrounding environment. Isolating pressure can prepare the cavity 112to receive a mixture of gases other than ambient air, such as a mixtureof therapeutic gases.

At 1104, the fluid regulator 120, such as the valve of the fluidregulator 120C, can be opened. Opening the valve of the fluid regulator120C can allow a fluid, such as a medicinal fluid, to flow out of thefluid source 170 into the processor module 140, such as into the mixingchamber 146 in communication with the pressure tube 117. In an example,the composition of the therapeutic fluid can be adjusted, such as bychanging the outflow rate of the fluid source, such as by opening andclosing the valve of the fluid regulator 120C. In an example, the valvecan be opened at a predetermined rate, such as to gradually increase theconcentration of medicinal fluid released into the mixing chamber 146over time.

At 1106, the pump 150 can be started to generate a volume draw, such asto generate a negative gauge pressure at the pump inlet 156. In anexample, the pump outlet 155 can be blocked, and the pump inlet 156 cancommunicate indirectly with the mixing chamber 146, such as the pumpinlet 156 can be in communication with the mixing chamber 146 throughthe pressure tube 117. For example, as the pump 150 generates a negativegauge pressure at the pump inlet 156, fluids in the mixing chamber 146,such as medicinal fluids, can be drawn through the pressure tube 117,such as through the pressure tube 117A into the cavity 112A, through thepressure tube 117C into the cavity 112B, and through the pressure tube117B into the pump inlet 156. In drawing the medicinal fluid from themixing chamber 146, the medicinal fluid can combine and mix with fluidsin the cavity 112 and the pressure tube 117, such as to create atherapeutic fluid. The composition of the therapeutic fluid can dependon the volume draw of the pump 150 and on the volume and concentrationof the medicinal fluid flowing through the fluid regulator 120C. In anexample, the composition of the therapeutic fluid can be adjusted, suchas by changing the volume draw of the pump 150. For example, the volumedraw of the pump 150 can be changed by increasing or decreasing thespeed of the pump 150, such as a centrifugal pump.

At 1108, a sensor 130, such as a gas sensor located in the cavity 112,can sense the therapeutic fluid flowing through the cavity 112, such asto sense an indication of the concentration of medicinal fluid in thetherapeutic fluid. The processor module 140 can receive a signal fromthe sensor 130, such as an electrical signal proportional to theindication of the concentration of medicinal fluid in the therapeuticfluid. The received sensor signal can be compared to a predetermined setpoint value, such as a physician-recommended concentration of medicinalfluid for the treatment of an eye condition, with the control circuit.If the received sensor signal is less than the predeterminedconcentration set point value, the valve of the fluid regulator 120C canbe further opened at 1107, such as to increase the concentration ofmedicinal fluid in the mixing chamber 146, and the therapeutic fluid canbe re-sensed at 1108. The valve of the fluid regulator 120C can continueto open until the received sensor signal, such as sensed in the cavity112, reaches the predetermined concentration set point value.

At 1110, the pump 150 can be stopped. After the received sensor signalmeets the pre-determined set point value, the therapeutic fluid can beconsidered adequately mixed in the apparatus 100 at the negative gaugepressure in the cavity 112. The pump 150 can then be stopped, such as tomaintain the negative gauge pressure in the apparatus 100.

At 1112, a sensor 130, such as a pressure sensor located in the cavity112, can sense the fluid pressure in the cavity 112, such as for anindication of therapeutic fluid gauge pressure. The processor module 140can receive a signal from the sensor 130, such as an electrical signalproportional to the gauge pressure of the therapeutic fluid. Thereceived sensor signal can be compared to a predetermined set pointvalue, such as a physician-recommended negative gauge pressure oftherapeutic fluid for the treatment of an eye condition, with thecontrol circuit. If the received sensor signal is greater than thepredetermined gauge pressure set point value, the speed of the fan 153can be increased at 1111, such as to increase the volumetric fluid drawin the mixing chamber 146, and the therapeutic fluid can be re-sensed at1113. The pump 150 can continue to generate volumetric fluid draw untilthe gauge pressure, such as sensed in the cavity 112, reaches thepredetermined gauge pressure set point value. In an example, the gaugepressure in the apparatus 100 can exceed the physician-recommendednegative gauge pressure, such as the negative gauge pressure in thecavity 112 can be less than the physician-recommended negative gaugepressure.

At 1114, the vent 144 can be adjusted. Adjusting the vent 144 can allowair from the surrounding environment to be drawn into the apparatus 100,such as to reduce the negative gauge pressure in the cavity 112. In anexample, the vent 144 can be adjusted by a predetermined method, such asto reduce the negative gauge pressure in the cavity 112 to within aspecified error band of the negative gauge pressure set point value,such as a physician-recommended negative gauge pressure.

At 1116, the valve of the fluid regulator 120C can be closed. Closingthe fluid regulator 120C can stop the medicinal fluid from flowing outof the fluid source 170. In an example, the valve can be closed at apredetermined rate, such as a rate selected to prevent concentrationchanges in the therapeutic fluid.

At 1118, the sensor 130 can sense an indication of the therapeutic fluidin the cavity 112, such as for a deviation from a specified set pointvalue. In an example, an indication of the concentration of medicinalfluid in the therapeutic fluid can be sensed by the gas sensor andcompared to the physician-recommended concentration set point level withthe control circuit, such as to a tolerance range (or error band)centered around the set point level. In an example, an indication of thenegative gauge pressure of the therapeutic fluid can be sensed by thepressure sensor and compared to the physician-recommended negative gaugepressure set point level with the control circuit, such as to atolerance range (or error band) centered around the set point level.When the sensed indication falls outside the tolerance range, the methodof 1100 can be reinitiated, such as at 1104, to adjust the sensedindication to a value within the tolerance range.

FIG. 12 shows an example method 1200 to control the level of water vapor(i.e. humidity) in the cavity 112, such as the level of humidityentrained in a therapeutic fluid. Maintaining physician-recommendedhumidity levels can enhance the effect of therapeutic fluids in contactwith the eye. However, condensate can form in the cavity 112, such asdue to the accumulation of perspiration. Control of humidity levels canimpede the formation of condensate while improving treatment efficacyand patient comfort during use of the apparatus 100.

At 1202, a sensor 130, such as a humidity sensor located in the cavity112, can sense an indication of the humidity level in the therapeuticfluid. At 1204, the indication of the humidity level in the cavity 112can be compared to a set point value, such as to determine if a humiditylevel has been achieved. In an example, the processor module 140 canreceive a signal from the sensor 130, such as an electrical signalproportional to the indication of the humidity level in the therapeuticfluid. The received sensor signal can be compared to a predetermined setpoint value, such as a specified humidity level for the treatment of aneye condition, with the control circuit.

At 1205, the humidity level in the therapeutic fluid can be adjusted. Ifthe received sensor signal is less than the humidity level set pointvalue, the valve of a fluid regulator 120 can be opened, such as toincrease the concentration of water vapor in the mixing chamber 146available for mixing into the therapeutic fluid, and the therapeuticfluid can be re-sensed and compared to the set point value at 904. Thevalve of the fluid regulator 120 can continue to open until the receivedsensor signal reaches the predetermined humidity level set point value.If the received sensor signal is greater than the humidity level setpoint value, a filter 158, such as a desiccant filter, can be exposed tothe therapeutic fluid, such as to at least a portion of the therapeuticfluid in the passage 157, to collect and remove excess water vapor.

At 1206, water vapor, such as water vapor entrained in the therapeuticfluid and accumulated condensate, can be collected from the apparatus100. Therapeutic fluid flowing through the passage 157, such as byoperating the fan 153 to circulate therapeutic fluid in the apparatus100, can be exposed to, such as can come in contact with, at least aportion of the desiccant filter, such as to collect water vapor from theapparatus 100. The amount of therapeutic fluid exposed to the desiccantfilter can be controlled by a slide valve, such as slide valve coveringthe desiccant filter and in communication with the control circuit ofthe processing module 140.

The control circuit can adjust the slide valve, such as to adjust thesurface area of the desiccant filter exposed to the therapeutic fluid,to control the rate at which water vapor can be extracted from thetherapeutic fluid.

Accumulated condensate, such as in the cavity 112, can be collected,such as with a wicking gasket 160. Condensate can come into contact withthe wicking core 162, such as a first surface 163 of the wicking core162, for absorption by the wicking core 162. Absorbed condensate candistribute through the wicking core 162, such as by osmosis, and can beretained within the wicking core 162.

At 1208, collected water vapor can be removed from the apparatus 100. Inan example, the desiccant filter, such as a desiccant filter saturatedwith water vapor, can be replaced in the pump 150, such as with a drydesiccant filter, to remove water vapor from the apparatus 100. In anexample, the desiccant filter can be exposed to the ambient atmosphere,such as to allow water vapor to evaporate from the desiccant. In anexample, the desiccant filter can include a heater element, such asintegrated into a desiccant filter, to increase the temperature of thedesiccant filter causing the collected water vapor to evaporate, such asinto the ambient atmosphere.

Accumulated condensate, such as condensate retained within the wickingcore 162, can be removed from the apparatus 100. In an example,condensate can migrate through the core cover 166, such as from theinterior surface 167 to the exterior surface 168, and evaporate from theexterior surface 168, such as to remove condensate from the apparatus100. In an example, a negative gauge pressure can be generated in thelumen of the suction tube 169, such as to draw condensate retained inthe wicking core 162 to the suction tube 169. The negative gaugepressure can be generated by a condensate pump including a pump separatefrom the apparatus 100, such as a standalone vacuum pump that can be incommunication with the control circuit of the processing module 140, anda pump included in the apparatus 100, such as the pump 150.

At 1210, the sensor 130 can sense an indication of the therapeutic fluidin the cavity 112, such as for deviation from a specified set pointvalue. In an example, an indication of the humidity in the therapeuticfluid can be sensed by the humidity sensor and compared to thephysician-recommended humidity set point level with the control circuit,such as to a tolerance range (or error band) centered around the setpoint level. When the sensed indication falls outside the tolerancerange, the method of 1200 can be reinitiated, such as at 1202, to adjustthe sensed indication to a value within the tolerance range.

VARIOUS NOTES & EXAMPLES

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In the event of inconsistent usages between this document and anydocuments so incorporated by reference, the usage in this documentcontrols.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

Method examples described herein can be machine or computer-implementedat least in part. Some examples can include a computer-readable mediumor machine-readable medium encoded with instructions operable toconfigure an electronic device to perform methods as described in theabove examples. An implementation of such methods can include code, suchas microcode, assembly language code, a higher-level language code, orthe like. Such code can include computer readable instructions forperforming various methods. The code may form portions of computerprogram products. Further, in an example, the code can be tangiblystored on one or more volatile, non-transitory, or non-volatile tangiblecomputer-readable media, such as during execution or at other times.Examples of these tangible computer-readable media can include, but arenot limited to, hard disks, removable magnetic disks, removable opticaldisks (e.g., compact disks and digital video disks), magnetic cassettes,memory cards or sticks, random access memories (RAMs), read onlymemories (ROMs), and the like.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription as examples or embodiments, with each claim standing on itsown as a separate embodiment, and it is contemplated that suchembodiments can be combined with each other in various combinations orpermutations. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

1. (canceled)
 2. An apparatus to adjust a fluid humidity level of afluid in a cavity over an anterior surface of a patient eye, theapparatus comprising: an enclosure, sized and shaped to form the cavityover the anterior surface of the patient eye, the enclosure including aninlet to receive the fluid and an outlet to return the fluid forrecirculation, the cavity configured to contain the fluid for contactwith the patient eye; a pressure source, in communication with theenclosure, configured to transfer the fluid to the inlet and receive thefluid from the outlet; and at least one of a humidifier or adehumidifier, in communication with the cavity, configured to adjust thefluid humidity level of the fluid in the cavity.
 3. The apparatus ofclaim 2, wherein the at least one of a humidifier or a dehumidifierincludes the humidifier.
 4. The apparatus of claim 2, wherein the atleast one of a humidifier or a dehumidifier includes the dehumidifier.5. The apparatus of claim 2, further comprising a processor module witha user interface, in communication with at least one of the pressuresource, the humidifier, or the dehumidifier, the processor moduleconfigured to allow a user to specify a set point including a fluidhumidity level set point.
 6. The apparatus of claim 5, furthercomprising a humidity sensor in communication with the processor moduleand the fluid, the humidity sensor configured to sense an indication ofthe fluid humidity level; and wherein the processor module is configuredto receive the indication of the fluid humidity level and generate acontrol signal to adjust at least one of the humidifier or adehumidifier.
 7. The apparatus of claim 6, wherein the at least one ofthe humidifier or the dehumidifier includes a manifold vent configuredto introduce an amount of ambient air into the cavity to adjust thefluid humidity level toward the fluid humidity level set point.
 8. Theapparatus of claim 7, wherein the control signal is configured to adjustthe manifold vent to introduce an amount of ambient air into the cavityto adjust the fluid humidity level toward the fluid humidity level setpoint.
 9. The apparatus of claim 6, wherein the at least one of thehumidifier or the dehumidifier includes a desiccant filter configuredfor exposure to the fluid to adjust the fluid humidity level toward thefluid humidity level set point.
 10. The apparatus of claim 9, whereinthe control signal is configured to adjust a slide valve to regulatefluid flow to the desiccant filter to adjust fluid humidity level towardthe fluid humidity level set point.
 11. The apparatus of claim 6,wherein the at least one of the humidifier or the dehumidifier includesa fluid regulator configured to regulate flow of a fluid stored in areservoir to the cavity to adjust the fluid humidity level.
 12. Theapparatus of claim 11, wherein the control signal is configured toadjust the fluid regulator to introduce an amount of the fluid stored inthe reservoir to the cavity to adjust fluid humidity level toward thefluid humidity level set point.
 13. A method to use an apparatus toadjust a fluid humidity level of a fluid in a cavity over an anteriorsurface of a patient eye, the apparatus including an enclosure, sizedand shaped to form the cavity, the enclosure including an inlet toreceive the fluid and an outlet to return the fluid for recirculation,the cavity configured to contain the fluid for contact with the patienteye, a pressure source in communication with the enclosure, configuredto transfer the fluid to the inlet and receive the fluid from theoutlet, and at least one of a humidifier or a dehumidifier incommunication with the fluid, configured to adjust the fluid humiditylevel of the fluid in the cavity, the method comprising: adjusting thefluid humidity level of the fluid to be delivered to the cavity usingthe at least one of the humidifier or the dehumidifier; delivering thehumidity-adjusted fluid to the cavity via an inlet of the enclosure; andreturning the humidity-adjusted fluid from the cavity via the outlet ofthe enclosure for recirculation using the pressure source.
 14. Themethod of claim 13, wherein adjusting the fluid humidity level includesdecreasing the fluid humidity level in the cavity with the dehumidifier.15. The method of claim 13, wherein at least one of a humidifier or adehumidifier includes a manifold vent and decreasing the fluid humiditylevel includes introducing an amount of ambient air through the manifoldvent into the cavity to adjust the fluid humidity level in the cavity.16. The method of claim 13, wherein at least one of a humidifier or adehumidifier includes a desiccant filter and decreasing the fluidhumidity level includes exposing the fluid to the desiccant filter toadjust the fluid humidity level in the cavity.
 17. The method of claim13, wherein adjusting the fluid humidity level includes increasing thefluid humidity level in the cavity with the humidifier.
 18. The methodof claim 13, wherein at least one of a humidifier or a dehumidifierincludes a fluid regulator and wherein increasing the fluid humiditylevel includes regulating flow of a therapeutic fluid stored in areservoir to the cavity to adjust the fluid humidity level in thecavity.
 19. The method of claim 13, wherein the apparatus furthercomprises a humidity sensor in communication with the cavity and whereinadjusting the fluid humidity level includes sensing an indication offluid humidity level in the cavity with the humidity sensor.
 20. Themethod of claim 19, wherein the apparatus further comprises a processormodule with a user interface in communication with at least one of thepressure source, the humidity sensor, the humidifier, or thedehumidifier, and wherein adjusting the fluid humidity level includesreceiving the indication of fluid humidity level in the cavity from thehumidity sensor with the processor module and generating a controlsignal with the processor module to adjust at least one of the pressuresource, the humidifier, or the dehumidifier.
 21. The method of claim 20,wherein generating the control signal includes generating a controlsignal to adjust at least one of the pressure source, the humidifier, orthe dehumidifier to change the fluid humidity level of the fluid towarda fluid humidity level set point.